Neutrino Masses and the Quest for UnificationNeutrino Masses and the Quest for Unification

K.S. BabuK.S. Babu

Oklahoma State UniversityOklahoma State University

Physics SeminarPhysics Seminar

Wichita State University, Wichita, KSWichita State University, Wichita, KS

November 6, 2013November 6, 2013

Cosmic Gall

Neutrinos, they are very small. They have no charge and have no

mass And do not interact at all.

The earth is just a silly ball To them, through which they

simply pass, Like dustmaids down a drafty hall

Or photons through a sheet of glass.

They snub the most exquisite gas, Ignore the most substantial wall, Cold-shoulder steel and sounding

brass, Insult the stallion in his stall.

And, scorning barriers of class, Infiltrate you and me! Like tall

And painless guillotines, they fall Down through our heads into the

grass.

At night, they enter at Nepal And pierce the lover and his lass

From underneath the bed—you call It wonderful; I call it crass.

John Updike Telephone Poles and Other Poems,

1963

• Postulated by Pauli as a desperate measure to restore momentum and energy conservation in beta decay (1930)

• Electron type neutrino discovered by Reines and Cowan in reactor experiments (1956) -- Nobel Prize in 1995

• Muon type neutrino produced in accelerators by Lederman, Schwartz, Steinberger et al (1962) – Nobel Prize in 1988

• LEP experiments measure N(nu) = 2.994 +-0.012 (1991-2002)• Neutrinos from the Sun detected by Davis et al (1968) – Nobel Prize in

2002• Neutrinos from Supernova 1987A detected in US and Japan -- Koshiba,

Nobel Prize in 2002• Neutrino oscillations discovered in atmospheric neutrinos [IMB,

Kamiokonde Hints (1988), Discovery by SuperKamiokande (1998)]• Solar neutrino deficit confirmed by various experiments and interpreted as

evidence for neutrino oscillations (1968 –)• Reactor antineutrino oscillations discovered – Daya Bay (2012), RENO,

DoubleChooz, T2K

A Brief History of Neutrinos

•

Neutrinos from the Sun

Neutrinos from the sky

L/E Dependence of atmospheric neutrinos

Daya Bay Reactor Neutrino Experiment

Global Fit to 3-Neutrino Oscilaltions

Minkowski (1977)Yanagida (1979)Gell-Mann, Ramond, Slansky (1979)Mohapatra, Senjanovic (1980)

Leptons

Quarks

Disparity a challenge for Quark-Lepton unified theories.

Neutrino mixing versus quark mixing

Neutrino Masses Probe the Scale of Unification of all Forces

The Greatest Equations Ever?

Tied for 1st place:

Top Finishers

Quantum Mechanics & Relativity

Dirac’s Equation (1927)

Antiparticles

Quantum Electrodynamics

Great Success of Quantum Electrodynamics

e

e

e

e+e-→+-

+

-

-

-

-

-

-

+

+

+

+

+

R +Test charge

-

+-R

-

-

-

-

-

-

+

+

+

+

+

+

q

g

g g

g g

Causes charge screening

Causes color charge anti-screening

Gross, Wilczek, Politzer Nobel Prize, 2004

Asymptotic freedom

ddu

uud

e, , W±, Z0

e,

Energy

1 GeV 102 GeV 1016 GeV 1019 GeV

With SUSY, Quadratic Divergence Cancels

SM ParticlesSM Particles SUSY PartnersSUSY Partners

Spin = 1/2 Spin = 0

Spin = 0 Spin = 1/2

Spin = 1 Spin = 1/2

More Hints in favor of GUTs

Standard Model

SO(10)

Structure of Matter Multiplets

Baryon asymmetry of the universe

Sakai, Yanagida (1982)

Weinberg (1982)

(Dimopoulos-Wilczek mechanism)

Proton Decay in Supersymmetric SO(10)

Dimopoulos, Wilczek (1981)Babu, Barr (1993)Barr, Raby (2000)

Babu, Pati, Wilczek (2000)Babu, Pati, Tavartkiladze (2010)

Gauge coupling evolution in explicit SO(10) model

Correlation between two modes of proton decay

Proton lifetime expectations

Model has only 11 real parameters plus 7 phases

Minimal SO(10) Model

Babu, Mohapatra (1993)Fukuyama, Okada (2002)Bajc, Melfo, Senjanovic, Vissani (2004)Fukuyama, Ilakovac, Kikuchi, Meljanac, Okada (2004)Aulakh et al (2004)

Bertolini, Frigerio, Malinsky (2004)Babu, Macesanu (2005)Bertolini, Malinsky, Schwetz (2006)Dutta, Mimura, Mohapatra (2007)Bajc, Dorsner, Nemevsek (2009)

Fit Input at GUT scale

Output: Type II Seesaw

Babu, Macesanu (2005)

Specific Example for Quark & Lepton masses

Theta(13) in Minimal SO(10)

Summary and Conclusions

Acknowledgments